Roller blind



FIG. 1 is a front elevational view of a roller blind showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a perspective view thereof;

FIG. 8 is a second perspective view thereof;

FIG. 9 is a third perspective view thereof;

FIG. 10 is a fourth perspective view thereof;

FIG. 11 is an enlarged view of portion 11 shown in FIG. 9;

FIG. 12 is an enlarged view of portion 12 shown in FIG. 9;

FIG. 13 is an enlarged view of portion 13 shown in FIG. 9;

FIG. 14 is an enlarged view of portion 14 shown in FIG. 9;

FIG. 15 is an enlarged view of portion 15 shown in FIG. 9;

FIG. 16 is an enlarged view of portion 16 shown in FIG. 9;

FIG. 17 is an enlarged view of portion 17 shown in FIG. 10;

FIG. 18 is an enlarged view of portion 18 shown in FIG. 10;

FIG. 19 is an enlarged view of portion 19 shown in FIG. 10; and,

FIG. 20 is an enlarged view of portion 20 shown in FIG. 10.

The dash-dot broken lines illustrated boundaries of the enlarged portions and do not form part of the claimed design. 

CLAIM The ornamental design for a roller blind, as shown and described. 